In recent years, an attempt has been made to further miniaturize a nonvolatile semiconductor memory device with memory elements each composed of a MOS transistor with a floating gate and to make higher the capacity of the nonvolatile semiconductor memory device. To realize the miniaturization and higher capacity, a next-generation nonvolatile semiconductor memory device using new materials and a different operating principle is being developed. A resistance-change memory has been considered as such a next generation nonvolatile semiconductor memory device.
A magnetoresistive random access memory (MRAM) using a tunnel magnetoresistive effect produced by a magnetic tunnel junction, a phase-change random access memory (PRAM) making use of the fact that a chalcogenide semiconductor phase-transits from a crystal phase to an amorphous phase or vice versa by Joule heat produced by current and the resistance in one phase differs greatly from that in the other phase, and the like have been developed. In addition, the development of new memories using other resistance-change materials and operating principles is on the rise. Those memories are generically called resistive random access memories (ReRAMs).